Solvents for dissolving an electrolyte salt for use in an electric double layer capacitor including at least one polarizable electrode as a positive electrode and/or a negative electrode should be stable when used at a withstand voltage of not lower than 3 V. To that end, use in combination of ethylene carbonate and propylene carbonate, which is a cyclic carbonate with a high oxidation potential (a high withstand voltage), has been proposed (Patent Document 1).    Patent Document 1: JP-A 2000-208372